Pediatricians in the United States are urging secondary and middle schools to delay start times to no earlier than 8:30 a.m. to give teens more time to sleep, in order to improve mental and physical health and academic performance. In a policy statement Monday, the American Academy of Pediatrics called sleep deprivation the most common, important and potentially remediable public-health risk among adolescents.

As teens hit puberty, their brains start secreting less melatonin and their “sleep drive” slows, both of which make it difficult to fall asleep at an earlier bedtime, according to the Academy’s statement. These factors, coupled with lifestyle issues and social demands such as homework, extracurricular activities and part-time jobs, mean the average teenager has difficulty falling asleep before 11 p.m. and is best suited to wake at 8 a.m. or later, the AAP said.

Earlier school start times – as early as 8 a.m. – have rankled parents who know their adolescent children aren’t getting enough sleep to function well in class. Teens need between nine and 10 hours of sleep every night, according to the Canadian Paediatric Society. (The AAP puts the requirement at 8.5 to 9.5 hours.)

In Canada, start times differ between and even within school boards. In Ontario, start times are staggered to co-ordinate bus schedules, but the majority of high schools commence classes between 8 and 8:30 a.m., and all start before 9 a.m., said Lori Foote of the Ontario Secondary School Teachers’ Federation.

Studies show that sleep deprivation in adolescents can negatively affect mood regulation, attention and memory.

Dr. Susan MacKenzie, a psychiatrist at the Centre for Addiction and Mental Health in Toronto, who works with youth who have mental-health and substance-use issues, says sleep is often a big part of the conversation with patients. Lack of sleep can worsen mood regulation and anxiety, she said. “When I’m trying to offer suggestions to help [patients], sleep hygiene and sleep routine are part of the discussion,” she said.

Young people ages 15 to 24 are more likely than any other age group to experience mental illness or substance-use disorders, according to CAMH. Further, while one in five Canadians will experience a mental-health or addiction problem in any given year, fully 70 per cent of mental-health problems have their onset during childhood or adolescence.

Lack of sleep can also negatively affect academic performance, something MacKenzie said contributes to anxiety and low confidence in youth. Young people who get more sleep see benefits in terms of mood stabilization, improvement in overall mood, a better sense of self, and feeling more capable of managing the demands of school. “We can’t underestimate the importance of sleep in that picture. I think it is definitely a factor, and perhaps we haven’t paid enough attention to it,” she said.

The Canadian Paediatric Society hasn’t pushed school boards to delay start times, said Dr. Stan Lipnowski, a member of the CPS board of directors and the adolescent-health committee. “It’s not something that we don’t care about, it’s just something that we have not yet got our hands onto,” he said.

Lipnowski said that while the evidence is clear that teenagers need more sleep, the bigger issue with later start times is implementation. “The rest of the world doesn’t revolve around a teen’s school hours,” he said. “From a physiological standpoint, there might be some benefit to [later start times], no denying it. The question is: How do you actually organize that? That’s probably the biggest hurdle.”

But MacKenzie says a half-hour shift toward a later start time isn’t an unreasonable proposition. “Sometimes we do things because it’s the way things have been done for a long time,” she said. “But it’s important to take new evidence into account and think about the next generation and what we’re hoping for in terms of happy, well-developed young people emerging into the adult world.”

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